Pettersson shot a 2-under 68 at the Sedgefield Country Club for a total of 259, breaking the tournament record score by six strokes. He birdied 13, 15 and 16 en route to his third win on the PGA Tour.
Scott McCarron, who led for a while in the final round, also carded a 68 to end up at 19-under 261.
Rich Beem, former PGA champion, shot his second straight 63 to finish third at 17-under 263.
"I felt great on the front nine, then started the back nine with two bogeys," Pettersson said. "My caddie gave me a great read on 12 and I made a long putt for par and that kind of turned things around. That was a momentum swing there and I played solid coming in."
Pettersson, a North Carolina resident, was born in Sweden but lived there just 10 years.
"I know I'm Swedish, but this (North Carolina) is home to me," he said. "I've really enjoyed the crowds this week. It's been fantastic. To win my home tournament is unbelievable."